1. Field of the Invention
The present invention relates in general to electric actuators for opening/closing an automotive door, and more particularly to the electric actuators of a type that, with the aid of power of an electric motor, opens and closes a back door that is pivotally connected to an open back end of a vehicle body.
2. Description of the Related Art
One of the electric actuators of the above-mentioned type is disclosed in Japanese Laid-open Patent Application (Tokkai) 2003-106044. The electric actuator of this publication is mounted in a roof structure of a vehicle body and generally comprises an electric motor and a connecting rod actuated by the electric motor to move in a fore-and-aft direction. A rear end of the connecting rod is pivotally connected to a pivotal back door, so that the fore-and-aft movement of the connecting rod produced by the electric motor induces closing and opening pivotal movements of the back door.
However, due to an inherent construction thereof, the above-mentioned electric actuator fails to have a sufficiently compact size. That is, in the electric actuator of the publication, the connecting rod is arranged to move beneath or below a base mechanism of the electric actuator, and thus the electric actuator has entirely a thicker construction. As is known, such thicker construction makes installation of the electric actuator in the roof structure rather difficult and tends to cause unsightly projection of a ceiling (or lower wall of the roof structure) into a passenger room.